1. Field of the Invention
The present invention relates to a display panel that may display an image using a liquid crystal element, an organic EL element or the like, and may be inputted with a position of a user finger or the like, and relates to a module using the display panel, and an electronic device using the display panel.
2. Description of the Related Art
Recently, a display device, which is used for a mobile phone and a personal digital assistant (PDA), a digital still camera, a PC (Personal Computer) monitor, and a television, uses liquid crystal elements or organic electroluminescence (EL) elements for display pixels. Such display pixels are arranged on a substrate in a matrix pattern together with driving transistors such as TFT (Thin Film Transistors).
On the other hand, a display device (touch panel) is proposed, in which photosensors are fabricated in the same layer as the TFT, thereby a position of a user finger or stylus may be detected (for example, Japanese Unexamined Patent Applications, Publication No. 2006-127212 and Publication No. 2007-128497). However, each of the display devices described in the Patent Application Publications uses a shadow formed by outside light or image display light to recognize a position of a finger or the like. Therefore, position detection has been hardly performed in the dark, or hardly performed when a display device emits no light, namely, in the case of black display.